Throttle-valve.



PATBNTEDMAR. 24', 190s.

K. RUSHTON. 'lflElRO'ITIFEA VALVE.

APPLIUATION FILED MAB 27, 1902 Ho MODEL TN: Ncmll: PETERS sa, PMoTuurHo.. wnsnmm'cm nA c UNrri-nn nSimfree PATENT Ormea.

KENNETH RUSHTON, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO BURNHAM, WILLIAMS & COMPANY, OF PHILADELPHIA, PENN- SYLVANI-A, A

,THRoTTLE-VALVE.

SPECIFICATION forming part of Letters VPatent N o. 723,734, dated March 24, 1903.

` Application filed March `27, 1902. Serial No. 100,212. (No model.)

To all whom it may concern:

.Be it known that I, KENNETH RUsHToN, a citizen of the UnitedStates, residing at Philadelphia, Pennsylvania, have invented' certain Improvements in Throttle-Valves, of whichr the following is a specification.

The main object of my invention is to construct a throttle-valve for admitting steam from the boiler into the cylinders of a locomotiveor other engine in which an auxiliary valve is used to admit steam to the cylinders while the locomotive, for instance, is drifting.

A further object is to wire-draw the steam through the valve-chamber, so that there will be a certain amount of back pressure under the main valve and that the said main valve can be more readily opened when desired.

In the accompanying drawings, Figure l is a sectional view through the valve andv valvechamber. Fig. 2 is a section on the line2 2, Fig. 1. the supplemental valve raised, and Fig. 4 is a sectional View showing the main valve raised.

A is the valve-casing,mounted in the steamdome of the boiler, having a neckA, which is coupled to the steam-supply pipe B, leading to the cylinders of the locomotive in the present instance. On the upper end of this casing is a seat o, and itting the seat is the main valve D. This valve has Wings d extending down to a ring ct, which closes openingsa",leadingto the neck A. Theseopenings a are formed in the body of the valve-cham ber A, as is also a small opening a2, preferably near the base of the said chamber, as clearly shown. This opening also communicates with the neck. The valve D is carried by a stem E, which passes through a central opening therein, the walls of the opening forming a seat d2, and on the stem'E is a sup,` plemental valve e, which fits on the seat. Ou the lower end of the stem are a nut and washer to provide a certain amount of lost motion in the stem, so that the supplemental valve e can be raised oif its seat on themain valve before the main valve is raised off its seat.

F is a lever pivoted at f to a projection on the valve-casing, and the stemE is connected to this lever. The lever inA turn is connected Fig. 3 is a sectional View showing'V by a link F to a bell-crank lever F2, also piva oted to a lug on the frame and connected to an operating-lever in the cab of the locomotive in the ordinary manner.

The area of the opening a2 in the valvecasing is much less than the area of the opening formed betweenthe small valve and its seat when the said valve is opened, so that the steam is wire-drawn from the valve-casing into the neck A. This necessarily makes a certain amount of back pressure in the casing A, so that there will be a pressure under the main valve to counteract to a certain degree the pressure on top of the main valve, so that Ywhen it isdesired to open the main valve it will open more readily owing to the factthat it isv partly balanced; but-when both valves are' closed themain valve is held firmly down to its seat by the boilerpressure.

It willbe seenV by using my improved throttlc-valve, which is especially adapted for locomotives, the engineer can close his 'main valve and open the auxiliary valve, as in Fig. 3, to allow a certain amount of steam to be admitted to the cylinders when the locomotive is drifting, and there is a greater amount of steam admitted than can pass from the valve-chamber through the opening a2. Consequently there s'a certain amount of back pressure within the valve-casing A, so that when it is desired to open the main Valve this back pressure will aid in the opening, Fig. 4, as it will tend to counterbalance the boilerpressure on the outside of the valve, thus making it much easier for the engineer to open the valve than where the valve is not balanced.

I claim as my inventionr,

l. The combination in a throttle-valve of a valve-casing, a steam-supply pipe, a main valve adapted to a seat in the valve-casing, a supplemental valve adapted to a seat in the main valve, said valve-casing having a main outlet and a supplemental outlet to thel steamsupply pipe, the area of said supplemental outlet being less than thearea ofthe opening of the supplemental valve, substantially as described.

2. The combination of the steam-supply pipe, a valve-casing having an inlet-opening roo communicating with the steam-chamber and an outlet-opening communicating With the steam-supply pipe, a valve arranged to close both the inlet and outlet openings and a supplemental Valve seated on the main valve, said valve-casing having a supplemental outlet to the steam-supply pipe, said supplemental outlet being of an area less than that of the opening closed by the supplemental valve, substantially as described.

3. The combination of a valve-casing having an inlet-opening, outlet-openings, a main valve having a portion closing the inlet-opening, and having a ring portion closing the outlet-openings, a stem upon which the main valve is mounted, said stem carrying a supplemenlal valve having its seat on the main valve, said stem having a certain amount of -lost motion so that when the stem is moved it will first raise the supplemental valve off its seat and lthen the main valve, the casing having a supplemental outlet-opening less in area than the opening of the supplemental valve, substantially as described.

4. The combination of a valve-chest having an inlet-opening at the top and outlet-openings communicating with the passage leading to the cylinders, a valve' having a main portion arranged to close the inlet-opening and having a ring portion arranged to close the u outlet-openings, a stern passing through the main portion of the valve and having the supplemental valve mounted thereon and seated in an opening in the main valve, said stem being connected to the main valve so as to allow the supplemental valve to be elevated off its seat before the main valve is opened, with a supplemental outlet-opening from the Valve-chest leading to the passage communicating With the cylinders, substantially as described. l

In testimony whereof I have signed my 4 

